1. Field of the Invention
This invention relates to a method of imaging fluorescence and a fluorescence imaging apparatus which are suitable for imaging fluorescence through observation extending over a long term, such as time-lapse observation, by interposing a liquid between an object to be observed, such as a living specimen, and an objective lens placed below the object.
2. Description of Related Art
In a conventional inverted microscope provided with an immersion objective, a common method of supplying a liquid to an immersion objective in microscopy is to manually pour the liquid by using a pipette. However, when a plurality of specimens are observed like microplate sample observation and time-lapse observation, or when a particular specimen is discontinuously observed for a long term, it is troublesome to manually pour the liquid with the pipette according to the need, and in addition, this imposes a load on a viewer. Thus, in the observation in which the inverted microscope provided with this type of immersion objective is used, the structure that the liquid can be automatically supplied to the immersion objective is proposed, for example, by Japanese Patent Publication No. 2004-531765.
FIG. 1 shows the structure that the liquid is automatically supplied to the immersion objective, set forth in Publication No. 2004-531765.
In FIG. 1, a supplier 51 provided as a liquid pouring means for supplying the liquid to the immersion objective is fixed to an immersion objective 52, and a supply tube 51a provided at the top of the supplier 51 extends close to a top lens 52a of the immersion objective 52 from the side of the immersion objective 52. The structure is such that the liquid can be automatically poured, through the supply tube 51a, between the top lens 52a of the immersion objective 52 and a specimen 54 supported by a specimen holder 53.
In FIG. 1, a trough-shaped absorption means 55 provided as a discharge means is placed around the immersion objective 52 and a discharge tube 56 is connected to the absorption means 55. A liquid flowing from the top lens 52a of the immersion objective 52 is stored in the absorption means 55 so that a stored liquid can be discharged through the discharge tube 56.